Classification of Foetal Distress and Hypoxia Using Machine Learning Approaches

© 2018, Springer International Publishing AG, part of Springer Nature. Foetal distress and hypoxia (oxygen deprivation) is considered as a serious condition and one of the main factors for caesarean section in the obstetrics and Gynecology department. It is the third most common cause of death in new-born babies. Many foetuses that experienced some sort of hypoxic effects can develop series risks including damage to the cells of the central nervous system that may lead to life-long disability (cerebral palsy) or even death. Continuous labour monitoring is essential to observe the foetal well being. Foetal surveillance by monitoring the foetal heart rate with a cardiotocography is widely used. Despite the indication of normal results, these results are not reassuring, and a small proportion of these foetuses are actually hypoxic. In this paper, machine-learning algorithms are utilized to classify foetuses which are experiencing oxygen deprivation using PH value (a measure of hydrogen ion concentration of blood used to specify the acidity or alkalinity) and Base Deficit of extra cellular fluid level (a measure of the total concentration of blood buffer base that indicates the metabolic acidosis or compensated respiratory alkalosis) as indicators of respiratory and metabolic acidosis, respectively, using open source partum clinical data obtained from Physionet. Six well know machine learning classifier models are utilised in our experiments for the evaluation; each model was presented with a set of selected features derived from the clinical data. Classifier’s evaluation is performed using the receiver operating characteristic curve analysis, area under the curve plots, as well as the confusion matrix. Our simulation results indicate that machine-learning algorithms provide viable methods that could delivery improvements over conventional analysis

Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin

Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies. An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects. Basal levels of oxytocin increased 3-4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum. Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin. Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother's brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does

Use of Lactate ProTM2 for measurement of fetal scalp blood lactate during labor – proposing new cutoffs for normality, preacidemia and acidemia : a cross-sectional study

Objective: Measurement of fetal scalp blood lactate is a supplementary tool to cardiotocography in the case of a non-reassuring tracing. Several hand-held lactate meters have been launched, all with differentials in absolute values. Therefore, the reference intervals must be calculated for each device. The internationally accepted reference interval is based on measurement with Lactate ProTM with recently got out of production. The aim of this study was to propose cutoffs for normality, preacidemia, and acidemia in fetal scalp blood for Lactate ProTM2 based on the comparison of lactate values measured with Lactate ProTM and Lactate ProTM2. Design: Seven hundred one fetal scalp blood samples were analyzed simultaneously. The conversion equations were retrieved from the linear regression model. On the basis of the cutoffs for Lactate ProTM cutoffs for Lactate ProTM2 were calculated. Results: The conversion equations obtained were Lactate ProTM = −0.02 + 0.68 × Lactate ProTM2 (SD: −0.09–0.07 × Lactate ProTM2) and Lactate proTM2 (LP2) = 0.03 + 1.48 × Lactate ProTM (SD: 0.16 + 0.17 × Lactate ProTM). The correlation to umbilical arterial pH was identical for the two devices (r = −0.18), whereas the correlation to umbilical arterial lactate was better for Lactate ProTM than for Lactate ProTM2 (r = 0.38, respectively, r = 0.33). The correlation to umbilical arterial lactate was dependent on time from sampling to delivery. Conclusion: Proposed reference values for Lactate ProTM2: scalp lactate 7.1 mmol/L = acidemia, expedite delivery

Proposed cutoff for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes : a large prospective observational study

Objective: Determination of lactate in fetal scalp blood (FBS) during labour has been recognised since the 1970s. The internationally accepted cutoff of >4.8 mmol/l indicating fetal acidosis is exclusive for the point-of-care device (POC) LactatePro™, which is no longer in production. The aim of this study was to establish a new cutoff for scalp lactate based on neonatal outcomes with the use of the StatstripLactate®/StatstripXpress® Lactate system, the only POC designed for hospital use. Design: Observational study. Setting: January 2016 to March 2020 labouring women with indication for FBS were prospectively included from seven Swedish and one Australian delivery unit. Population: Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 weeks of gestation. Method: Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations. Main outcome measures: Metabolic acidosis in cord blood defined as pH 10 mmol/l and/or lactate >10 mmol/l. Results: A total of 3334 women were enrolled of whom 799 were delivered within 25 minutes. The areas under the receiver operating characteristics curves (AUC) and corresponding optimal cutoff values were as follows; metabolic acidosis AUC 0.87 (95% CI 0.77–0.97), cutoff 5.7 mmol/l; pH <7.0 AUC 0.83 (95% CI 0.68–0.97), cutoff 4.6 mmol/l; pH <7.05 plus BDecf ≥12 mmol/l AUC 0.97 (95% CI 0.92–1), cutoff 5.8 mmol/l; Apgar score <7 at 5 minutes AUC 0.74 (95% CI 0.63–0.86), cutoff 5.2 mmol/l; and pH <7.10 plus composite neonatal outcome AUC 0.76 (95% CI 0.67–0.85), cutoff 4.8 mmol/l. Conclusion: A scalp lactate level <5.2 mmol/l using the StatstripLactate®/StatstripXpress® system will safely rule out fetal metabolic acidosis. Tweetable abstract: Scalp blood lactate <5.2 mmol/l using the StatstripLactate®/StatstripXpress system has an excellent ability to rule out fetal acidosis

Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial

Objective To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth